Technical Field
The present disclosure generally relates to wireless communication between processor-based systems.
Description of the Related Art
Wireless power allows a powered system or device to be provided with power without the use of wires. A wireless power transmitter system transfers energy wirelessly to a wireless power receiver system. Inductive coupling may be used to transfer electromagnetic energy between the wireless power transmitter system and the wireless power receiver system. The energy that is transmitted to the wireless power receiver system may be used by the wireless power receiver system to charge a chargeable power source (e.g., rechargeable battery) of the wireless power receiver system, and to provide power to components of the wireless power receiver system to allow the components to operate.
Near field communication (NFC) is a set of short-range wireless communications technologies, typically requiring a distance of 10 centimeters (cm) or less and operating at 13.56 MHz. Generally, NFC involves an initiator and a target. NFC peer-to-peer communication may be used provided both devices are powered. The initiator may also actively generate an RF field which may power a passive target. This feature enables NFC targets to take very simple form factors such as tags, stickers, key fobs, or cards which do not require batteries.
NFC tags store data and may be read-only or may be rewriteable. The NFC tags can securely store data such as payment card information, loyalty program data, PINs, device identifiers, and other information. NFC tags can also store data or instructions which may be used to permit a device to issue commands, requests, notifications, etc., to another device.
NFC uses magnetic induction between two antennas or coils located within each other's near field, effectively forming an air-core transformer. As noted above, NFC systems may utilize one of two modes, passive communication mode and active communication mode. In passive communication mode, the initiator device provides an RF carrier field and the target device answers by modulating the existing field. In this mode, the target device may draw its operating power from the initiator-provided electromagnetic field. In the active communication mode, both the initiator device and the target device communicate by alternately generating their own fields. A device deactivates its RF field while the device is waiting for data from another device. In this mode, both devices may initiate an NFC session since each device has a power supply, but such increases the costs, the size and the complexity of the devices.